<span>In order to do this, you have change the alkene into an
alkyne. That is the aim of Br2/CH2Cl2 trailed by NaNH2. The Br2 with form a vic
dihalide (3,4-dibromo octane). Adding of NaNH2 will execute two E2 reactions.
-NH2 will eliminate an H from carbons 3 and 4. This double elimination will make
the alkyne. Then handling the alkyne with H2/Lindlar will form the cis alkene. The
final product will be CIS-3-octene.</span>
Hydrogen bonds are not like covalent bonds. They are nowhere near as strong and you can't think of them in terms of a definite number like a valence. Polar molecules interact with each other and hydrogen bonds are an example of this where the interaction is especially strong. In your example you could represent it like this:
<span>H2C=O---------H-OH </span>
<span>But you should remember that the H2O molecule will be exchanging constantly with others in the solvation shell of the formaldehyde molecule and these in turn will be exchanging with other H2O molecules in the bulk solution. </span>
<span>Formaldehyde in aqueous solution is in equilibrium with its hydrate. </span>
<span>H2C=O + H2O <-----------------> H2C(OH)2</span>
Answer:
a) if the liquid is not vaporized completely, then the condensed vapor in the flask contains the air which is initially occupied before the liquid is heated. When calculating the molar mass of the vapor the moles of air which are initially present are not excluded, so that the molar mass of the vapor would be an increase in value.
b) While weighing the condensed vapor, the flask should be dried. If the weighing flask is not dried then the water which is layered on the surface of the flask is also added to the mass of the vapor. Therefore, the mass of the vapor that is calculated would be increase.
c) When condensing the vapor, the stopper should not be removed from the flask, because the vapor will escape from the flask and a small amount of vapor will condense in the flask. Therefore, the mass of the condensed vapor would be In small value.
d) If all the liquid is vaporized, when the flask is removed before the vapor had reached the temperature of boiling water, then the boiling
temperature of that liquid would be lower than that of the boiling temperature of the water.Therefore, the liquid may have more volatility.
The answer is (2). The Lithium has 3 protons and 4 neutrons. For every neutral atom, it will have the same number of protons and electrons. Because the proton has one positive charge and electron has one negative charge and neutron does not have charge.
Water is the only one of these that would work by process of elimination.
